Cooper Discoverer AT3 4S Review

My 4S’s are living up to their 4 seasons name. Breakup (aka mud season) is in full effect in Alaska, and these tires keep amazing me. The snow is gone, that pic is from a couple weeks ago, and we had our first small rain storms yesterday. Lots of mud but these tires don’t care!

Oh yeah, we must have gotten summer gas again too as I’m suddenly getting the same 20-21mpg I got last year on the stock Hankooks. I was getting 18-19 after switching 4wd off for the summer, was getting 16-17 most of the winter.

 

Just over 32k on these tires right now - still around 10/32nds tread all around, wearing evenly with regular rotations. Running them 32 cold in the summer, heating up to 35-36 depending on temp swings in the day and on the highway. I never seem to get more than 30k on a set of tires before I feel I'm losing some tight control and wet pavement confidence. These are driving just like new over a year later and I actually think I'll get 50k easily. Not bad for inexpensive tires that do well off-road, in the rain, light mud, snow, etc.,

 

Anyone have problems getting these to balance? I have them on my 2019 4runner and I've had them balanced 4 times now and they still cause a steering wheel wobble/vibration at 50-60 mph.

They've been road force balanced 3 times and one regular balance.

 

Weird - I've had no issues with mine whatsoever. still smooth as butter over a year later. maybe luck of the draw? if you got certs maybe can get them swapped?

 

No issues here. Got about 2000 on them I’d assume and they run great.

So quiet I can hear my suspension squeak

 

Finally took them out in some pretty loose mud yesterday. It had rained a good deal over the last few days, so I was interested to see how they do.

Well enough, didn’t get stuck, but they left A LOT to be desired in slick off road conditions. It won't keep me from going out more, but I wouldn’t be rambling solo anywhere crazy without some solid recovery gear or a buddy that has some.

 

good to know

yeah, definitely not a MT tire by any means. I try to avoid tons of mud these days after a handful of muddy adventures when I bought the truck - too much hassle cleaning that shit up after it coats the underside of the truck. hard to get it ALL I suppose. outside of that, it's the best all around tire I've owned in terms of smooth/quiet highway, tight control, wet performance, traction on rock and gravel, dirt, snow, and it's not terrible in ice...

there's a guy in my neighborhood with his KM2s on his 3rd gen that I can hear coming from 1/2 mile away... wha wha wha wha wha

 

Oh yeah, I bought these knowing full well they’re a regular AT and I expect AT results. Just posting that the XLTs will still spin a good deal.

This just means I need 5.29s to get more fluid lower end power...

 

Torrential can’t see rain? Lots of standing water? AT3’s don’t care!

 

So I got a set of these the other day.

This is my first truck and first set of oversized tires I've ever put on a vehicle. It's definitely noticeable having a slightly larger and heavier tire on my I4. I see now why it's advisable to do suspension at the same time because the shocks are certainly not suited for the added bit of weight.

Ride feels plush otherwise and there's no noticeable noise unless I turn the sound system off and strain to listen for the difference.

All in all I like these tires and am looking foreward to using them in the dirt. They really balanced the look of the truck, too.

 

As long as you’re not expecting MT or aggressive AT (ST Maxx, Duratrac, NRG, R/T, etc.), you’ll be happy.

I’m not in mud / slick dirt enough to mind over all the other benefits.

 

Part of me wishes I had waited and done it with wheels and suspension, but I got a good price on my take offs so it only set me back about $600 for all five.

I can live with everything but I should've just stayed with the stock size for the time being. The Taco has plenty of clearance for my needs for the time being. Not looking to take my DD/Work truck down any road it wont come back from.

 

Unless the tires are in the bed, the suspension does not “feel” the added weight of bigger tires (i.e. it is unsprung weight).

 

Not with regular forward motion, but going over bumps the shock absorber has to absorb the shock and return everything to it's static position. A job made slightly more difficult when your shocks have to slow down the up and down motion of a heavier tire. Right?

That's my theory anyways, not an expert.

 

Thanks for the reviews everyone! I just picked up a set for my Ford Ranger (Wish it was a Tacoma... this thing is constantly demanding parts) and they're pretty awesome so far.

 

enjoy. mine are solid as can be still, my wife even asked me last weekend if I had bought "new tires again!?" which of course I hadn't, but the tread is just hovering around 10/32nds all around and has for more than 10k. they wear really well and even in my case and for once I feel their warranty coverage isn't BS like I've witnessed in the past with many other tires

 

My Cooper 4S took some serious abuse this weekend up near Idyllwild. Lots of jagged rocks on the trails, about baseball size. I hate those ones. A few bigger rocks I took my time going over, some sand. Never lost traction in my prerunner!

This pic was towards the end of the trip. Already had about 35 miles of trails on them before we headed back down

 

I have AT3's not the newer 4s and I have had issues on these. It may be one specific tire that is worse. It is almost as the tire gets flat spots like old bias ply tires did. If truck sits for a few day is when it is the most noticeable. Especially if I get on the freeway after only a few miles on the road. After a good 15-20 miles it improves. Don't now if this is do to tire temp building or just road force. Next set if I experience the same thing I will try more to determine if it is just one tire than request it be replaced.

 

From June, headed back to Kantishna in Denali National Park.

Kantishna-3594 by David Dawson, on Flickr

Kantishna- by David Dawson, on Flickr
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I have used the older version AT3 and also had issues balancing. This week I had the AT3 4s put on my 2010 tacoma and they run down the road silky smooth.